The Knoxville Fire Department's arson unit has charged two homeless men with the massive fire last month at the McClung Warehouse.

The two remaining historic buildings caught fire on February 1. They were so heavily damaged, they had to be demolished for safety reasons.

Two men, Robert Earl Montgomery, 60, and Joey Patrick Bryant, 32, were taken into custody around 10:30 Sunday night. Both were charged with criminal trespass. Montgomery faces a charge of assault (threat of injury). Bryant is also charged with aggravated assault (intentional or knowing).

According to the arrest warrants, Bryant, Montgomery, and a women broke into the building around 3:20 am on Saturday. The two men are accused of intentionally starting the fire with a lighter. When the fire got out of control, the three ran from the building, and even changed their clothes to avoid detection.

After the fire, the two men threatened the woman to keep her from going to the police. The warrant said that Bryant hit her with his fist and threatened her with a knife.

She was not charged.

Bryant was arrested Sunday evening as he arrived to work as part of a freelancing cleanup crew at Thompson Bowling Arena.Montgomery was arrested at a homeless camp near the intersection of Oldham Ave. & Davana St. around 8:30 p.m.

"Long hours, hard work, and a joint effort by the Bureau of Alcohol Tobacco Firearms, Knoxville Police Department, Knox County Fire Marshal's Office, and the Knoxville Fire Department led to the arrests," said KFD Captain D.J. Corcoran in a press release.

Robert Montgomery(Photo: KCSO)

Joey Patrick Bryant(Photo: KCSO)

The massive fire happened nearly seven years after another fire devastated the property. The city had hoped to find a developer to revitalize the historic buildings, but they had to be razed. The city still plans to issue a Request for Proposals (RFP) to determine what will happen to the site on Jackson Avenue.

The cost of the fire was estimated at approximately $1.3 million dollars.

In the late 1800s, the McClung Warehouses were used primarily as a shipping headquarters for the McClung Hardware and Supplies Company. (Undated photo) (Photo: WBIR)

Nov. 14, 2013: The City of Knoxville announces it is buying the remaining McClung Warehouses from a bankruptcy court for $1.45 million with the intention of finding a developer to rehab the property. (Photo: WBIR)